The present invention relates to an implantable connector and remote connector assembly for coupling electric leads to implantable devices.
Body implantable electronic devices capable of artificially stimulating an organ, such as the heart, to correct or modify its behavior are well known. In the case of the heart, stimulation is accomplished by transmitting electrical impulses from an implanted cardiac device via electrical leads to electrodes disposed in appropriate areas of the heart muscle tissue. Several different types of impulse-generating devices have been developed to provide a variety of electrical impulses in response to various organ malfunctions.
Generally speaking, most devices which are implantable comprise (1) a small, self-contained sealed unit which includes a source of electrical energy, and (2) an electronic device for producing impulses at appropriate intervals. After preliminary testing of the device, it is surgically implanted into a subcutaneous cavity. Electrodes at one end of electrical leads are implanted in the organ tissue, while the other end of the electrical leads extend to the device and are coupled to it so a to provide the necessary electrical connection.
Conventional methods of coupling electrical leads to the device are comparatively elaborate. An example of such a convention coupling device is shown in FIGS. 1A and 1B. To couple or terminate a lead, the device 1 is provided with a female conductive member 2 having an elongated passage 3 for receiving a male electrode tip member (not shown) attached to the end of the electrical lead. A threaded hole 4 extends through the side of female member 2 into passage 3. The male member is slipped into the passage (in the direction of arrow B in FIG. 1B) and a set screw 5 is then screwed into threaded hole 4 by means, such as a small wrench (not shown), which tightly urges screw 5 against the side of the male connector. This procedure is repeated for every electrical lead being coupled to the implanted device.
Because devices such as cardiac pacemakers must remain in the body for years, electrical leads need to be reliable. Several problems could occur if the leads are not connected in such a way that body fluids are inhibited from contact with the conductive portions of the leads. For instance, electrolysis could occur at the connection with the male member of the lead, causing the connection to deteriorate. A conductive path of body fluids could also cause attenuation of electric signals passing through the connection and, in the case of multiple connections, cause electrical crosstalk. Furthermore, the seals which are described in the prior art necessitate the manipulation of extremely small screws, seals and the like, which is both time consuming and difficult.
Previously the leads for implanted devices have been terminated in a connector that is rigidly attached to the device. This requires the leads to be taken from the site they stimulate, known as the lead to body interface, to the site of the implanted device. A device which is implanted a remote distance from a plurality of lead to body interfaces requires a surgeon performing the implant to route the leads a relatively long distance through the body between the device and site to be stimulated, referred to as "tunnelling." When either the implanted device or the implanted lead must be removed or serviced, it is frequently necessary to also remove the electrode lead and subsequently perform another tunnelling operation. This adds to the length and complexity of the surgical procedure, both of which are undesirable results.